The present invention is in the field of automotive power distribution boxes, and more particularly the cover portion (usually the xe2x80x9clowerxe2x80x9d cover) covering wires or wire bundles.
Power distribution boxes (PDB""s) are commonly used in the automotive industry to streamline wiring by eliminating multi-branch wiring. A power distribution box consolidates branch circuits and fuses, connecting vehicle battery power to various electrical components. Small gauge electrical wires, numbering in the dozens or hundreds, are typically bound or bundled together in a xe2x80x9cwire harnessxe2x80x9d leading to a PDB, where the wires are connected internally to mating terminals and connectors.
Referring to FIG. 1, a typical PDB arrangement is illustrated on an interior vehicle panel 10. A first wire harness 12, and in particular a branch 13b thereof, is routed into a first power distribution box 14 for electrical interconnection with a first set of consolidated branch circuits and fuses and further with the wires and circuits of a second harness 18 whose branch 18a is routed through a second power distribution box 16 and an interconnect harness 15.
Referring to FIGS. 2 and 3, power distribution box 14 is shown disassembled into its three basic components: a xe2x80x9cbasexe2x80x9d 14c for mounting power terminals, connectors, wire terminating and rerouting structure, fuses, busbar and other known structure, sandwiched between and enclosed by protective upper and lower covers 14a, 14b. PDB base 14c will typically include a number of vertically oriented partitions, sockets, or terminals for making wire harness connections.
Various subsets of terminated wires 13a, 13b, 13c, etc. emanate from the lower side of base 14c and are merged by bundling or sheathing into the various wire harnesses such as 13b and 15 entering or exiting the PDB 14 from either side. The panel-or-through-like PDB structure illustrated is fairly typical, particularly in interior vehicle panel installations to accommodate the limited space between the vehicle panel 10 and any decorative and/or insulative interior covering. It will be understood by those skilled in the art, however, that the exemplary PDB structure illustrated in FIG. 2 is but one of many known variants whose specific shape and internal structure varies from application to application.
In general, the PDB wiring bundles 13a, 13b, 13c, etc. contained by the lower cover 14b have a tendency to rattle against the sides of the cover during vehicle operation. This is particularly irritating to vehicle operators and passengers when the PDB is installed in an interior vehicle panel as illustrated in FIG. 1, making the rattle quite audible to the occupants of the vehicle. Since unexplained rattles and the like are not only irritating but difficult to diagnose by the repair facility to which a rattle-prone vehicle is inevitably brought, automotive manufacturers place an emphasis on eliminating audible rattle in vehicle components, including the PDB.
A common prior art solution to the problem of rattling wires in a PDB is to glue or otherwise secure a shaped block of open-cell foam into the lower cover. The foam in its uncompressed state typically has sufficient volume that the wire bundles must first partially compress the foam before the PDB base 14c can be mated with the lower cover. Such foam-type solutions, while reducing and even eliminating rattle, are expensive and interfere with the assembly of the PDB, particularly in high volume wire bundle applications. Another problem with foam is that a standard PDB may be used in several locations in a vehicle or on different vehicles, in some cases accommodating high volume wire bundles and low volume wire bundles. Since the PDB""s are pre-manufactured, the foam tends to be cut to a standard size and volume, which may be too great for high volume wire bundles and not enough to prevent the rattling of low volume wire bundles.
The present invention is an anti-rattle structure molded directly into the plastic wire cover of a PDB, equally suitable for both high volume and low volume wire bundles to prevent rattle of even low volume bundles without hindering the assembly of high volume bundles. The interior of the cover (usually the xe2x80x9clowerxe2x80x9d cover) is provided with a plurality of transverse, generally U-shaped ribs extending up each side and across the bottom of the cover. A plurality of the ribs are spaced along the length of the trough to define a reduced volume, reduced surface area passage for the wires which keeps the wires away from the flat, noisy plastic sidewalls and bottom of the cover.
In the preferred form, the upper ends of each rib are beveled or chamfered to smoothly guide wires extending from the PDB base into position as the parts of the PDB are being assembled.